Bowl lift jack mounting for earthmoving scraper

ABSTRACT

A connection between the upper end of a bowl lift jack and tubular spreader of a bowl draft frame which connection is in the form of a gimbal having a spindle which extends through and is supported for rocking motion in one direction in the tubular spreader and has a bifurcated end or yoke outside of the spreader with journals thereon for supporting the jack for rocking motion in a direction normal to the first direction.

United States Patent [451 Apr. 25, 1972 Hamilton [541 BOWL LIFT JACK MOUNTING FOR EARTHMOVING SCRAPER {72] Inventor: Thomas R. Hamilton, Crest Hill, 111.

[73] Assignee: Caterpillar Tractor Co., Peoria, 111.

[22] Filed: Feb. 9, 1970 [21] Appl. No.: 9,604

[52] US. Cl ..37/129, 308/22 [51] Int. Cl. ..E02f 3/62 [58] Field ofSearch ..37/129,126,118,124;

[56] References Cited UNITED STATES PATENTS 2,535,301 12/1950 Tourneau ..280/5 2,852,870 9/1958 Kimsey et a1. ..37/126 3.175.846 3/1965 Arbaugh ..280/492 X 3.179.440 4/1965 Bumby ..280/492 3,262,513 7/1966 Henriksson et a1 ..280/492 UX 3,529,676 9/1970 Moe et a1. 172/707 X 3,553,860 1/1971 Fisher et a1. ..37/129 3,015,173 l/l962 Kimsey et al... 37/129 H 3,014,291 12/1961 Kirchler 37/129 H 2,451,294 10/1948 McGee ..37/129 Primary Examiner-Robert E. Pulfrey Assistant ExaminerR. E. Suter Attorney-Fryer, Tjensvold, Feix, Phillips & Lempio [57] ABSTRACT 2 Claims, 4 Drawing Figures PATENTED APR 2 5 I972 SHEET 10F 2 INVENTOR THOMAS R. HAMWJVON BY A W M 9h 1 ATTORNEYS "E IEAFR 2 5 I572 SHEET 2 [IF 2 84- INVENTOR THOM A5 R. HAM LTON ATTORNEYS BOWL LIFT JACK MOUNTING FOR EARTHMOVING SCRAPER In many scrapers, a draft frame is pivoted to the scraper bowl and hydraulic motors or jacks connect the frame and the bowl to pivot the bowl about the axis of its ground-engaging wheels to raise and lower its forwardly disposed cutting edge with respect to the ground. Since loading and stresses are very high, unintended motions occur between the draft frame and the bowl and it becomes desirable to secure the jack to these parts by means permitting universal movement. Gimbals have been used to connect the jacks with the tubular spreader of the draft frame. In one known construction, the gimbals are supported on a heavy metal ring which embraces and is welded to the spreader. The rings are very large in some cases weighing several hundred pounds each and require a great deal of costly and time-consuming welding.

The present invention eliminates a great part of the weight of the known construction referred to and mounts the spindle portion of the gimbal within the tubular spreader. Since this lowers the position of the jack, a special fitting is provided to effect raising thereof to its proper position.

A more complete understanding of the invention will be had upon reading the following specification where it is described in detail by reference to the accompanying drawings.

IN THE DRAWINGS FIG. 1 is a view in side elevation of a scraper fitted with bowl lift jacks embodying the present invention;

FIG. 2 is an enlarged sectional view showing the manner in which a jack is supported with respect to the tubular draft frame spreader and taken on the line lI-II of FIG. 3;

FIG. 3 is a fragmentary view looking downwardly on the structure shown in FIG. 2; and

FIG. 4 is a fragmentary view in rear elevation of the assembly taken along the line IV-IV ofFIG. 2.

In FIG. 1, a scraper of well-known design is shown as having a tractor portion generally indicated at 10, a bowl l2 and a draft frame 14 connecting the tractor and bowl. The draft frame 14 is pivoted to the sides of the bowl as at 18 and the bowl is held in a raised or carry position by hydraulic jacks, one of which is shown at 20, forming an adjustable connection between a tubular spreader shown at 22 which extends transversely of the draft frame and the bowl. Upon extension of the jack 20, the bowl 12 is permitted to swing downwardly about the center of its supporting wheels 24 until its cutting edge shown at 26 engages earth to be loaded into the bowl. The usual apron 28 closes the forward end of the bowl when it is full and is manipulated by a jack partially shown at 30 and connected through a lever 32 and suitable linkage to the draft frame 14. One of the jacks 20 is shown in FIG. 2 as connected to spreader 22 by a gimbal structure which has a spindle 34 supported for rotation on an axis parallel to the longitudinal center line of the tractor and scraper. The spindle is supported in bearing bushings, one of which is shown at 36 and the other at 38. The bushing 36 fits within a large tube 40 extending all of the way through the spreader tube and the bushing 38 is carried in a smaller ring-shaped part 42 which extends through only the front wall of the spreader. The spindle is held against retraction by a plate 44 secured to its end as by cap screws 46. The plate 44 is generally circular but has one flat side adjacent which a lug 48 is secured to the ring 42. This prevents excessive rotation of the spindle which might occur during assembly or when the jack is partially disconnected. Reinforcing rings shown at 50 and 52 encircle the ends of the tube 40 and ring 42 and are welded to these parts and also to the spreader tube 22. Further reinforcing is provided by semi-circular webs 54 and 56 welded in place above and below the tube 40 within the spreader 22. Openings 58 and 60 are provided in the webs so that conduit and wiring for hydraulic and electrical components may be passed therethrough.

At its rear end, the spindle 34 carries a yoke 62 with outwardly extending journals 64 at its opposite sides as best shown in FIG. 3. The 'ournals extend into suitable bushings carried by hearing brac ets 66 which, as shown in F IGS. 2 and 4, are held in place by cap screws 68 extending through a flange 70 at the lower end of the jack cylinder. A circle of cap screws 72 also extends through this flange and secures a closure plate 74 to the end of the cylinder with a suitable opening therein through which a piston rod 76 extends. The lower end of the rod 76 is connected by a ball and socket joint indicated at 80 to brackets 82, on a beam 84 (See also FIG. I) which extends transversely across the forward portion of the bowl between its sidewalls. This assembly permits full universal movement of the jack with respect to the bowl and the draft frame so that the jack structure is not subjected to excessive stresses.

In previous constructions where the spindle was mounted on top or a slight distance above the tubular spreader 22, it was connected with the jack cylinder by trunnions intermediate its upper and lower ends. The jack was sufficiently high to enable it to raise the bowl to the proper carry position illustrated in FIG. 1. In the present design in which the spindle is disposed at a lower position, the connection thereof to the jack below its lower end enables raising of the bowl to its proper carry position.

Iclaim:

1. In a tractor scraper combination which includes a tractor, a scraper with a wheel supported bowl and a draft frame connecting the tractor and bowl and including a spreader tube having a longitudinal axis between draft arms which are pivoted to the bowl, and at least two jack means extending between the spreader tube and the bowl for raising and lowering the forward end of the bowl about the axis of its wheels, the improvement which comprises a connection between the spreader tube and each jack means, each connection comprising a spindle extending through the longitudinal axis of the spreader tube, sleeve means extending entirely through the spreader tube, bearing bushings in the sleeve means receiving the spindle, and reinforcing webs extending between the exterior of the sleeve means and the interior of the spreader tube whereby the spindle is supported for rocking motion about an axis parallel to the longitudinal axis of the tractor and scraper, and a yoke extending rearwardly from the spindle including a pivotal connection between said yoke and the lower end of the jack means, said spindle including a generally circular plate having one flat side and said spreader tube including means to engage said plate to prevent excessive rotation of said spindle.

2. The combination of claim 1 in which the jack has a piston rod extending downwardly through said yoke, and a pivotal connection between the lower end of said rod and the scraper bowl. 

1. In a tractor scraper combination which includes a tractor, a scraper with a wheel supported bowl and a draft frame connecting the tractor and bowl and including a spreader tube having a longitudinal axis between draft arms which are pivoted to the bowl, and at least two jack means extending between the spreader tube and the bowl for raising and lowering the forward end of the bowl about the axis of its wheels, the improvement which comprises a connection between the spreader tube and each jack means, each connection comprising a spindle extending through the longitudinal axis of the spreader tube, sleeve means extending entirely through the spreader tube, bearing bushings in the sleeve means receiving the spindle, and reinforcing webs extending between the exterior of the sleeve means and the interior of the spreader tube whereby the spindle is supported for rocking motion about an axis parallel to the longitudinal axis of the tractor and scraper, and a yoke extending rearwardly from the spindle including a pivotal connection between said yoke and the lower end of the jack means, said spindle including a generally circular plate having one flat side and said spreader tube including means to engage said plate to prevent excessive rotation of said spindle.
 2. The comBination of claim 1 in which the jack has a piston rod extending downwardly through said yoke, and a pivotal connection between the lower end of said rod and the scraper bowl. 